There are three places that spring to mind. 1. The old Pirate's Cove on Paradise Island (I think now just called the cove): You'll probably need Atlantis passes. This is a natural cove that almost thins to a lagoon at the entrance. approx 200 yds north south and 500 yds east west. the mouth is about 200 yds east west and has large triangular blocks of concrete across it. I've seen large sting ray (5') very close to the shore, nurse sharks come scavenging in the evening. The concrete blocks play host to a plethora of fish.(Site Averages 20 FT ish)
2. The beach area west of caves point in front of Orange hill. This is mostly sand and grass. Stand as high as you can on the road to get vantage then look for the dark spots in the sea. Hopefully these are coral. Directly out from Orange Hill about half way to the drop off is a large patch. Maybe a half mile out. Collect sea biscuits and sand dollars on the way out and see plenty of fish, lobster once you're there. Take an indirect route back in, to the west, you should hit patches of grass. see conch and maybe even see a few shells. I've seen a HUGE spotted eagle ray here, earlier this month.(Site averages 15Ft ish)
3. Finally Clifton Park. An area far to the west (Far? on an island 25 by 7 miles!?! I've been here too long!) After much crying and Whining Security are now letting folk park and walk down to the sea. 200Yds. find the old rough cut ramp and head slightly to the right of straight out, toward the nearest white buoy. that marks the James Bond Cessna. Maybe two hundred yds out. This area is deeper than the other two and depending on the current at the time you may enjoy a fresh coating of diesel fuel from the near by power stn. But, coral heads start from about fifty yds out and if you can remember where you saw those other buoy’s from the shore you could even get to see the other James bond wrecks or the sunken Plane from that Jessica Alba flick or even the David Tucker Wreck.
(Site averages 35 Ft ish)
Don't expect unspoiled reef. This is a well trodden path.
Good Luck!